Serum lipid and lipoprotein tests are used as diagnostic indicators of disorders of lipid metabolism and related diseases. The tests that are commonly performed by people visiting hospitals today include
I. Total cholesterol measurement
Cholesterol (CHO) is one of the constituents of lipids. 70% of cholesterol is cholesterol ester and 30% is free cholesterol, which is called total cholesterol (TC).
Serum TC levels are influenced by various factors such as age, family, gender, genetics, diet, and psychology. The measurement of TC is often used as a reference indicator for the prevention, estimation of the onset and observation of the efficacy of atherosclerosis. increased TC is commonly found in.
1, cardiovascular and cerebrovascular diseases caused by atherosclerosis.
2, various hyperlipoproteinemia, obstructive jaundice, hypothyroidism, lipid-like nephropathy, nephrotic syndrome, diabetes mellitus, etc.
3, long-term smoking, alcohol consumption, mental tension and blood concentration, etc.
4, application of certain drugs, such as cyclosporine, glucocorticoids, aspirin, oral contraceptives, beta-adrenergic blockers, etc.
5, hyperthyroidism.
6, severe liver diseases, such as cirrhosis and acute hepatic necrosis.
7, anemia, malnutrition and malignant tumors, etc.
8, the application of certain drugs, such as estrogen, thyroxine, calcium antagonists, etc.
Second, triglyceride measurement (TG)
Serum TG is affected by lifestyle, diet and age, and fluctuates widely within and between individuals. Due to the short half-life of TG, exogenous TG can be significantly increased after eating a high-fat, high-sugar and high-calorie diet. Therefore, specimens for TG measurement must be collected intravenously at 12-16 hours of fasting to exclude and reduce the effects of diet.
Increased TG is seen in.
1, coronary artery disease.
2, primary hyperlipidemia, atherosclerosis, obesity, diabetes, gout, hypoparathyroidism, nephrotic syndrome, high-fat diet and obstructive jaundice.
Hypotonic TG is seen in.
1, hypobeta-lipoproteinemia and anaphylaxis.
2. severe liver disease, malabsorption, hyperthyroidism, and hyperaldosteronism.
III. Serum lipoprotein determination
Lipoprotein is the form of lipid presence, transport and metabolism in blood, and the examination of lipoprotein can understand the quality and quantity of lipid.
The ultra-high speed centrifugation method classifies lipoproteins according to different densities into.
1. celiac particles (CM).
2. very low density lipoproteins (VLDL).
3, low-density lipoprotein (LDL).
4. high-density lipoprotein (HDL).
5, intermediate density lipoprotein (IDL), a metabolite of very low density lipoprotein.
(1) HDL measurement
HDL increase: HDL increase has an important role in preventing atherosclerosis and coronary heart disease. Premenopausal women with higher HDL levels have a lower prevalence of coronary heart disease than men and postmenopausal women. Chronic hepatitis, primary biliary cirrhosis, etc. Decreased HDL: atherosclerosis, acute infections, diabetes, chronic renal failure, nephrotic syndrome, and the application of drugs such as androgens, beta-blockers and progesterone.
(2) LDL measurement
Increased LDL: To determine the risk of coronary heart disease. LDL is a risk factor for atherosclerosis, and increased LDL level is positively correlated with the occurrence of coronary heart disease. Others: hereditary hyperlipidemia, hypothyroidism, nephrotic syndrome, obstructive jaundice, obesity and application of androgens, β-blockers, glucocorticoids, etc. Decreased LDL: common in absence of β-lipoproteinemia, hyperthyroidism, malabsorption, cirrhosis, and low-fat diet and exercise.